Cape Town, June 30 (DPA) Cristiano Ronaldo's World Cup adventure ended on a sour note Tuesday as he faced accusations of spitting at a cameraman following Portugal's 1-0 loss to Spain in the Round of 16.

Ronaldo has had a poor tournament, and under his captaincy Portugal failed to score in three of their four games - reflecting his own difficulty in finding the net.

As he stomped off the pitch after Portugal were rolled over by a dominant Spain, Ronaldo looked directly into a camera tracking him and seemed to aim a big wad of saliva at the feet of the cameraman.

Whether it was intentional or not is unclear, but many users on Twitter lambasted the superstar for being a poor loser.

The Real Madrid man created great expectations ahead of the tournament, but he has played second fiddle to the likes of Spain's David Villa - whose fourth goal in South Africa won the game for Spain - and Argentina's Gonzalo Higuain, also on four goals.

Ronaldo scored only once, in Portugal's 7-0 thumping of North Korea, but even then he needed several lucky bounces off his back and head to present him with the opportunity.

It was his first international goal in 16 months, and his time in South Africa is now likely to be remembered mainly for an apparent act of petulance.